不同菜地土壤的铁氨氧化脱氮过程探究

采集了不同菜地的土壤，分析其理化性质.采用同位素示踪技术测定了铁氨氧化、反硝化和厌氧氨氧化的速率，运用Miseq高通量测序技术探究了菜地土壤的群落组成.结果表明，铁氨氧化速率在种植蔬菜的土壤显著高于裸地的土壤，并且铁氨氧化速率与土壤Fe（III）（r = 0.736， P < 0.05）和总有机碳（r = 0.575， P < 0.05）均有显著的正相关.另外，在不同菜地中5种主要的铁还原菌（芽孢杆菌属，假单胞菌属，嗜酸菌属，脂环酸芽孢杆菌属，梭状芽胞杆菌属）被检测到，并且铁还原菌的相对丰度在种植蔬菜的土壤（1.38%~2.19%）比在裸地的土壤（0.75%）高.在脱氮贡献方面铁氨氧化， 反硝化和厌氧氨氧化分别贡献了7.3%~12.4%， 53.1%~72.3%和18.9%~36.4%的氮气产生，说明铁氨氧化是菜地中重要的微生物脱氮路径.

Investigation of nitrogen removal by feammox in soils from different vegetable fields

In this study, we measured the potential rates of feammox, denitrification and anammox by isotope tracer technique insoil samples collected from different vegetable plots. In addition, we also analyzed theirphysicochemical characteristics, and the composition of microbial community via Miseq high-throughput sequencing technology. The results showed that the feammox rates in the vegetable soil samples were significantly higher than those from the bare land. Moreover, there exists a significant relationship between the feammox rates and Fe(III)(r = 0.736, P < 0.05), and total organic contents (r = 0.575, P < 0.05). Additionally, five predominant iron-reducing genera (Bacillus, Pseudomonas, Acidiphilium, Alicyclobacillus, Clostridium) were detected among the different vegetable soil samples, and the relative abundance of iron-reducing bacteria was higher in the vegetable soil samples (1.38%~2.19%) than in bare land soil samples (0.75%). Feammox, denitrification and anammox were estimated to account for approximately 7.3%~12.4%, 53.1%~72.3% and 18.9%~36.4% of the total nitrogen removal, respectively. Overall, the results of this study indicate that feammox could be an important pathway for nitrogen removal in the vegetable fields.